Just put him in jail.
As far as I can tell, this isn't a case of a hedonistic famous guy and a ditzy underage chick in the seventies when nobody cared. It's a case of a grown male drugging, raping and sodomizing a 13 year old child, pleading guilty and then fleeing before sentencing.
I'm not a fan of the age of consent thing, but this isn't even about that. She didn't consent in either sense of the word - she said no. He pled guilty, but fled justice. If that's the case, then he gets to serve the sentence now.